It may be the primary translation, but that doesn't mean it's always the most appropriate. In the context of sports, it gives this:
a. to play
Practicar tenis es un ejercicio estupendo para el cuerpo entero.Playing tennis is a great workout for the entire body.
You cannot just use the first definition. Sometimes you have to consider the context of the word. In this case, practicar deportes means play sports, not practice them. That's what the Spanish means.